Plastic shotgun shell



Dec. 26, 1967 E. A. SOBOLEWSKI PLASTIC SHOTGUN SHELL Filed Feb. 11, 1966 FIG. 4

INVENTORY EDWARD A. SOBOLEWSKI ATTORNEY FIG. 3

United States Patent 3,359,903 PLASTIC SHOTGUN SHELL Edward A. Sobolewski, 19850 State Line, South Bend, Ind. 46637 Filed Feb. 11, 1966, Ser. No. 526,789 3 Claims. (Cl. 102-43) ABSTRACT OF THE DISCLOSURE A plastic shotgun shell having a series of spaced recesses at the point of juncture between the base and side walls and a lip overlapping the hole for the primer. The base is provided with a series of recesses in its periphery spaced inwardly from the end thereof.

The conventional shotgun shell consists of a cylindrical body portion, a base normally formed integrally with one end of the cylindrical portion, and a cap recessed in the base and extending therethrough. In the past, attempts have been made to produce shotgun shells of plastic, particularly shotgun shells of the reloading type, but there have been a number of inherent difiiculties which have interfered with production or have prevented them from performing satisfactorily and/or from being reloaded and reused. These include the molding of the shell with a relatively thin cylindrical portion and a relatively thick base without distortion or flaws; the permanent distortion created during firing of the shell which virtually destroys the shell for further satisfacory reuse; and the sealing of the cap in the base so that gases are not discharged around the cap when the shell is fired. If any one of these conditions occurs, the shell is unsatisfactory and unsafe. Since plastic has certain inherent properties which make it suitable for such shells, this material can can be universally and extensively used for the shells in place of the conventional paper and brass construction if the foregoing dificulties are avoided. It is therefore one of the principal objects of the present invention to provide a shotgun shell structure and design which can easily be fabricated by standard molding or casting processes without the creation of flaws in the thicker section, and which can be reloaded and reused satisfactorily over and over without any appreciable diminution in performance.

Another object of the invention is to provide a plastic shotgun shell which is so constructed and designed that the firing cap can be easily inserted and removed when the shell is reloaded, and which effectively seals the cap in the base of the shell so that no gases are discharged around the cap and the surrounding wall of the base when the shell is fired.

Still another object of the invention is to provide a plastic shotgun shell which will maintain its dimensions within the required tolerances throughout repeated reloading and firing of the shell and which can be handled in the gun loading and ejecting operations in all important respects the same as the conventional shell.

Additional objects and advantages of the invention will become apparent from the following description and accompanying drawings, wherein:

FIGURE 1 is a side elevational view of a shotgun shell embodying the present invention;

FIGURE 2 is a top plan view of the shotgun shell shown in FIGURE 1;

FIGURE 3 is a transverse cross sectional view of the shell, the section being taken on line 33 of FIGURE 1;

FIGURE 4 is a longitudinal cross sectional view taken on line 44 of FIGURE 1; and

FIGURE 5 is a view of the end of the present shell opposite that shown in FIGURE 2.

3,359,903 Patented Dec. 26, 1967 Referring more specifically to the drawings, numeral 10 designates generally the present shotgun shell, 12 the cylindrical sidewalls, 14 the base of the shell joined integrally with the sidewalls, and 16 a firing cap seated in the center of base 14. Shotgun shells of the present structure and design may be made in various gauges and can be satisfactorily used with various size shot and charges. The caps, likewise, may be varied to satisfy requirements.

The cylindrical sidewalls 12 are tapered throughout their length from the lower end to the upper end, and are provided with a slight offset at numeral 17 where the wadding ends and the seal is normally placed. The internal portion of the cylindrical sidewall is reinforced by a plurality of fins 18, consisting, in the arrangement shown, of six radially positioned fins equally spaced around a center portion 20, the center portion consisting of an inwardly extending protrusion on the base 14. The fin-like portions formed by the reinforcing structure provide substantial strength to the lower portion of the cylindrical sidewalls to prevent excessive expansion and permanent deformation when the shell is fired, and yet they do not interfere with the molding operation.

The base 14 consists of a generally disc-shaped structure having an outer portion 22 of disc-shaped configuration and an inner portion 24 joined integrally to the sidewalls 12. The two portions 22 and 24 are connected by an intermediate structure 30 of star-shaped configuration, forming recesses 32 spaced equally around the base and separated by protrusions 34, the two portions 22 and 24 defining an annular groove 36. The recesses and protrusions provide satisfactory strength for the base so that it will maintain its shape throughout repeated uses of the shell and yet permit the relatively heavy base sections to be molded without distortion or flaws. The marginal edge 38 of the base provides the usual flange for seating over the shell ejecting mechanism of the gun and permits the shell to be ejected as effectively as conventional shotgun shells.

One of the difliculties which has been encountered with plastic shells in the past has been the tendency of the shell base to expand slightly when the shell is fired, thus permitting gases to pass between the cap and the base surrounding the cap. This renders such shells unsatisfactory, and this condition often becomes more pronounced as the shell is reused, such that occasionally the caps will not remain in place in the shells while they are being carried or shifted preparatory to being fired. It is therefore one of the important features of the invention to provide a satisfactory seal which will effectively remain operable to prevent the expulsion of gases escaping at the base of the shell, regardless of the number of times that the shell is fired. As seen in FIGURE 4, the base is provided with protrusion 20 which projects around the inner end of the cap and which is provided with an internal annular flange 40 with a lip 42 extending over or overlapping the inner end of the cap. This annular flange and lip are curved inwardly and downwardly to a relatively thin edge adjacent the inner edge of the cap sidewalls. The base is provided with an annular recess 43 extending completely around boss 44 and interrupted only by fins 18. The recess around the center boss concentrates the gas pressure on the sidewalls of the boss as the shell is fired, thus holding the boss firmly around the cap and minimizing expansion of the boss. The base is also provided with an annular recess 45 for receiving the conventional flange 46 of the cap so that the outer end of the cap is flush with the end surface of the base.

In the fabrication of the present shotgun shell, the mold is designed to form fins 18 and recesses 32, to produce the relatively thin but strong base, such that only slight and inconsequential shrinkage occurs in the base and cylindrical side portions during the molding opera-tion. Thus the shell can be formed with rapid mass production equipment without resulting in flaws or otherwise unsatisfactory structures. The shells may be formed of a variety of different plastic materials, such as polyethylene or nylon, for example, and the thickness of the cylindrical sidewalls and base portions can be varied, depending upon the size of the charge and extent of anticipated reuse of the shell.

In the use of the present shell, the cap 16 is inserted in the vase in the manner illustrated in FIGURE 4 and the powder, wadding and shot are then inserted in the hollow interior of the shell. When the shell is fired, the impact of the explosion presses on the upper side of annular flange 40, pressing it and the lip 42 downwardly against the inner end of the cap, thus inherently and automatically forming a tighter seal between the base and the cap so that the gases cannot escape; i.e. as the pressure increases, the efiectiveness of the seal between the lip 42 and the inner end of the shell 16 likewise increases, so that an effective seal is maintained regardless of the force or size of the charge. Further, the gas pressure in recess 43 against the external surface of boss 44 prevents expansion of the boss and augments the seal between the shell base and the cap. When the shell is to be reloaded, the cap can be easily punched outwardly from the base by inserting a rod in the open end of the shell and into the cap through the opening defined by lip 42. Pressure applied to the rod will cause the cap to slip from the hole in the base without distorting or otherwise damaging the base, lip or annular member 40.

In a modified form, fins 18 and/or recesses 32 may be omieted so that either or both the internal and external walls are straight and uninterrupted. While only one embodiment of the present invention has been described in detail herein, various changes and modifications may be made without departing from the scope of the invention.

I claim:

1. A plastic shotgun shell, comprising a disc-shaped base having opposite end faces and having a hole extending axially therethrough for receiving a primer cap, a relatively thick generally annular portion extending from one end face and surrounding said hole, said annular portion having an annular flange at the end removed from said one end face extending radially into said hole, said flange having a lip at the end removed from the annular portion for engaging an inner end of said cap and forming a seal therewith, and a tubular side wall having one end connected integrally with said annular portion, said sidewall and said annular portion defining in cross-section an annular groove surrounding said annular portion within said side wall, and a plurality of spaced fins in said groove connected between said annular portion and said sidewall defining a plurality of recesses in said groove.

2. The plastic shotgun shell as defined in claim 1, in which said base, said side wall and said annular portion define a plurality of recesses equally spaced around the external periphery of said shell.

3. The plastic shotgun shell as defined in claim 2, in which adjacent radial portions of said base defining said recesses are straight and are joined together at their inner and outer edges.

References Cited UNITED STATES PATENTS 3,215,077 2/1965 Mayer et al 102-44 3,292,538 12/1966 Umbach et al 102-4l 3,309,994 3/1967 Lage 102-42 FOREIGN PATENTS 999,458 l/ 1952 France.

BENJAMIN A. BORCHELT, Primary Examiner.

ROBERT F. STAHL, Examiner. 

1. A PLASTIC SHOTGUN SHELL, COMPRISING A DISC-SHAPED BASE HAVING OPPOSITE END FACES AND HAVNG A HOLE EXTENDING AXIALLY THERETHROUGH FOR RECEIVING A PRIMER CAP, A RELATIVELY THICK GENERALLY ANNULAR PORTION EXTENDING FROM ONE END FACE AND SURROUNDING SAID HOLE, SAID ANNULAR PORTION HAVING AN ANNULAR FLANGE AT THE END REMOVED FROM SAID ONE END FACE EXTENDING RADIALLY INTO SAID HOLE, SAID FLANGE HAVING A LIP AT THE END REMOVED FROM THE ANNULAR PORTION FOR ENGAGING AN INNER END OF SAID CAP AND FORMING A SEAL THEREWITH, AND A TUBULAR SIDE WALL HAVING ONE END CONNECTED INTEGRALLY WITH SAID ANNULAR PORTION, SAID SIDEWLL AND SAID ANNULAR PORTION DEFINING IN CROSS-SECTION AN ANNULAR GROOVE SURROUNDING SAID ANNULAR PORTION WITHIN SAID SIDE WALL, AND A PLURALITY OF SPACED FINS IN SAID GROOVE CONNECTED BETWEEN SAID ANNULAR PORTION AND SAID SIDEWALL DEFINING A PLURALITY OF RECESSES IN SAID GROOVE. 